Significant stuff in the comments in both directions, mostly illustrating that Patri's using a somewhat over-simplified standard here. That is, his main conclusion is correct -- in the broad sense, motorcycles are much more dangerous than cars -- but it's far less clear to me that that's true in the specific case I'm looking at. (Scooter on a lowish-speed road.) More dangerous, certainly, but it's not clear that that's an overwhelming issue...